Mercedes-Benz Forum banner

21 - 36 of 36 Posts

·
Premium Member
2004 CLK 240 Coupe
Joined
·
11,379 Posts
Key: filter, not pump...no banjo bolt issue, just the funky spring clamps on the hoses.
Greg. I agree that the OP was only talking about changing the fuel filter - which had possibly been changed before. However, I would have thought that if you were going into that area with the clamps, etc, you would do both pump and filter at the same time. The filter is a 75k mile service, isn't it?

I did see a fuel filter DIY in the W210 stickies, but not one for a fuel pump, so maybe it will be useful.
 

·
Registered
'01-E320 & 02-ST2
Joined
·
31,631 Posts
Greg. I agree that the OP was only talking about changing the fuel filter - which had possibly been changed before. However, I would have thought that if you were going into that area with the clamps, etc, you would do both pump and filter at the same time. The filter is a 75k mile service, isn't it?

I did see a fuel filter DIY in the W210 stickies, but not one for a fuel pump, so maybe it will be useful.
Although on some models there are pump problems, the pumps on the 210 seem to last quite a while. Given that, and that a quality one isn't exactly cheap, I can't see changing one as part of routine maintenance.


OTOH, if you were changing the pump, I would indeed also change the filter; that way you clamp things off, remove the assembly, swap things out on the workbench, then crawl back under.

Just my .02.
 

·
Registered
Joined
·
6 Posts
Hello everyone!! This is my first post; hope everyone is doing well and that there are people out there able to help me. As mentioned here, my car (1999 e320 sedan) also has to take a couple seconds before starting up. It will fire right up on overnight cold starts but will have this problem if left off after approximately 15 minutes. I have just changed the fuel pump, sparkplugs, oil+oil filter, air filter, and have also cleaned the key. I have also tried leaving the key in the last position before on and then starting it but that didn’t work either. My friends and I know much about cars but we cannot figure this out. Thank you!
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
8,009 Posts
If you have a fuel pressure gauge,connect it to the schrader valve at the fuel rail.

Start the engine and take readings when the engine is idling. Then switch the engine off and check the drop of the fuel pressure. It should be above 43 psi immediately after the engine is turned off. If it drops fast it is the fuel pump check valve. After 30 minutes, if it goes below 36 psi, you may have leaky fuel injector(s). This may cause long cranks when the engine is hot.

Fuel pump check valve will cause long cranks even if the engine is cold. And you said you already replaced the fuel pump. I assume you also replaced the fuel filter ?
 

·
Registered
Joined
·
6 Posts
If you have a fuel pressure gauge,connect it to the schrader valve at the fuel rail.

Start the engine and take readings when the engine is idling. Then switch the engine off and check the drop of the fuel pressure. It should be above 43 psi immediately after the engine is turned off. If it drops fast it is the fuel pump check valve. After 30 minutes, if it goes below 36 psi, you may have leaky fuel injector(s). This may cause long cranks when the engine is hot.

Fuel pump check valve will cause long cranks even if the engine is cold. And you said you already replaced the fuel pump. I assume you also replaced the fuel filter ?
Hi! I replaced the fuel pump but not the filter unfortunately.
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
8,009 Posts
A dirty and clogged up filter causes drivability issues. If your engine starts with a short cranking when cold, and then starts with a long crank 15 minutes later after the engine is fully warmed up (I assume), it is not likely related to a filter.
 

·
Registered
Joined
·
6 Posts
A dirty and clogged up filter causes drivability issues. If your engine starts with a short cranking when cold, and then starts with a long crank 15 minutes later after the engine is fully warmed up (I assume), it is not likely related to a filter.
My cold starts are golden; never have a problem with that. Also, I have no issues while driving except for the fact that during idle my vehicle shakes. It only has a long crank approximately after 15 minutes; yet if I were to turn it off then turn it right back on it would start. I hope these details help a little. Thank you very much.
 

·
Premium Member
1998 E320 base sedan @ 160kmiles
Joined
·
8,009 Posts
Well, the theory is that if you have a leaky injector, when the engine is hot, the fuel leaked into the cylinder evaporates and generates a very rich mixture with small amount of air (oxygen). The cylinder will not fire under this conditions. When you retry cranking after that, the fuel vapor is pushed out by previous long crank, and the mixture is not too rich anymore.
 

·
Registered
Dallas, Texas
Joined
·
8,585 Posts
My cold starts are golden; never have a problem with that. Also, I have no issues while driving except for the fact that during idle my vehicle shakes. It only has a long crank approximately after 15 minutes; yet if I were to turn it off then turn it right back on it would start. I hope these details help a little. Thank you very much.
Most likely you have pissing injector. Connect fuel pressure tester designed for CIS (k-jet) between fuel feed line and injector rail. Valve on tester facing feed. On 1 2 3 with aid of helper shut engine off and close the valve. Observe pressure. Any pressure loss indicates leaking injector.
 

·
Registered
Joined
·
6 Posts
Okay I have noted all these. Thank you for the help. I might have to sell my car. Does anyone know what this will do to my car if the injector is left unchanged?..Basically how much time I have left with this car.
 

·
Registered
Joined
·
6 Posts

·
Registered
Joined
·
664 Posts
You're likely going to have to fix this issue because prospective buyers will notice it on a test drive and expect it to either be fixed or for you to drastically lower your sale price to account for the cost of fixing it.
 

·
Registered
Joined
·
6 Posts
You're likely going to have to fix this issue because prospective buyers will notice it on a test drive and expect it to either be fixed or for you to drastically lower your sale price to account for the cost of fixing it.
Do you know the cost of the fix?
 

·
Registered
Dallas, Texas
Joined
·
8,585 Posts
Do you know the cost of the fix?
Injector is $83.50. About three hours of labor to lift injector rail, determine which one is leaking and replace it.

 
21 - 36 of 36 Posts
Top